North Korea conducted its sixth and most powerful nuclear test at Punggye-ri, causing a magnitude-6.3 earthquake. 2017 North Korean nuclear test: North Korea conducted its sixth nuclear test on 3 September 2017, claiming it had tested a thermonuclear weapon. While unconfirmed, analysts agree the test was likely of a thermonuclear or boosted fission weapon. The test took place at a high point of the 2017–2018 North Korea crisis. September 3, 2017. Wiki link